6299cf9ec3
We enable power management automatically for bridges where pci_bridge_d3_possible() returns true. However, these bridges may have ACPI methods such as _DSW that need to be called before D3 entry. For example in Lenovo Thinkpad X1 Carbon 6th _DSW method is used to prepare D3cold for the PCIe root port hosting Thunderbolt chain. Because wake is not enabled _DSW method is never called and the port does not enter D3cold properly consuming more power than necessary. Users can work this around by writing "enabled" to "wakeup" sysfs file under the device in question but that is not something an ordinary user is expected to do. Since we already automatically enable power management for PCIe ports with ->bridge_d3 set extend that to enable wake for them as well, assuming the port has any ACPI wakeup related objects implemented in the namespace (adev->wakeup.flags.valid is true). This ensures the necessary ACPI methods get called at appropriate times and allows the root port in Thinkpad X1 Carbon 6th to go into D3cold. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.